Flexible, open-cell thermoset foams and blowing agents and methods for making same

Abstract

Disclosed are methods and compositions for forming a flexible, open cell viscoelastic foams which utilize a thermosetting composition comprising one or more components capable of forming a thermoset matrix and a blowing agent comprising at least one chemical blowing agent, such as water, and at least one physical blowing agent selected from the group consisting of trans-1-chloro-3,3,3-trifluoropropene (HFCO-1233zd(E)), 1,1,1,3,3-pentafluoropropane (HFC-245fa); 1,1,1,3,3-pentafluorobutane (365mfc), blends consisting essentially of at least about 80% of HFC-365mfc and 1,1,1,2,3,3,3-heptafluoropropane (227ea), and combinations of any two or more of these.

1 . A method of forming a flexible, open cell polyurethane molded foam having a target IFD at 65% comprising:
 (a) providing a foamable, thermosetting composition capable of forming an open-cell, flexible polyurethane foam, said composition comprising: (i) one or more polyol components; (ii) one or more isocyanate components, and (iii) blowing agent comprising water and at least one physical blowing agent, said physical blowing agent being present in an amount effective to reduce the free-rise density of the foam by at least about 5% relative to the same foam made without the physical blowing agent;   (b) molding said foamable composition to form a molded foam; and   (c) prior to and/or simultaneous with said molding step, ensuring that the IFD at 65% of said molded foam is not more than 15% less than the target IFD at 65% by carrying out one or more of the following steps:
 (1) including in said foamable composition an polymer modifying agent in an amount effective to increase the IFD at 65% of said molded foam; 
 (2) conducting said molding step by overpacking said mold in amount effective to increase the IFD at 65% of said molded foam; 
 (3) increasing the index of said foamable composition by an amount effective to increase the IFD at 65% of said molded foam; and 
 (4) including in said foamable composition an amount of polymeric polyol so as to increase the IFD at 65% of said molded foam. 
   
     
     
         2 . The method of  claim 1  wherein said step (c) comprises including in said foamable composition a polymer modifying agent in an amount effective to increase the IFD at 65% of said molded foam. 
     
     
         3 . The method of  claim 1  wherein said step (c) comprises conducting said molding step by overpacking said mold in amount effective to increase the IFD at 65% of said molded foam. 
     
     
         4 . The method of  claim 1  wherein said step (c) comprises increasing the index of said foamable composition by an amount effective to increase the IFD at 65% of said molded foam. 
     
     
         5 . The method of  claim 1  wherein said step (c) comprises including in said foamable composition an amount of polymeric polyol so as to increase the IFD at 65% of said molded foam. 
     
     
         6 . A method of forming a flexible, open cell polyurethane foam comprising:
 (a) providing a foamable, thermosetting composition capable of forming an open-cell, flexible polyurethane foam, said composition comprising: (i) one or more polyol components; (ii) one or more isocyanate components, and (iii) blowing agent comprising water and at least one physical blowing agent selected from the group consisting of trans-1-chloro-3,3,3-trifluoropropene (HFCO-1233zd(E)), 1,1,1,3,3-pentafluoropropane (HFC-245fa); 1,1,1,3,3-pentafluorobutane (365mfc), blends consisting essentially of at least about 80% of HFC-365mfc and 1,1,1,2,3,3,3-heptafluoropropane (227ea), and combinations of any two or more of these; and   (b) forming from said foamable composition a flexible, open cell polyurethane foam comprising a matrix comprising said thermoset polymer and a plurality of open cells in said matrix, said foam having a free-rise density that is at least about 5% less than the density of the free-rise density of the foam formed from said same composition but in the absence of said physical blowing agent and having an IFD at 65% of not more than 20% less than the IFD at 65% of said same foam but without said physical blowing agent.   
     
     
         7 . The method of  claim 6  wherein said forming step comprises molding said foamable composition. 
     
     
         8 . The method of  claim 6  wherein said forming step comprises slab forming said foamable composition. 
     
     
         9 . A automotive seat cushion containing a foam formed according to the method of  claim 7 . 
     
     
         10 . A foamable composition for forming a flexible, open cell polyurethane foam comprising:
 (a) one or more polyol components;   (b) one or more isocyanate components;   (c) blowing agent comprising water and at least one physical blowing agent selected from the group consisting of trans-1-chloro-3,3,3-trifluoropropene (HFCO-1233zd(E)), 1,1,1,3,3-pentafluoropropane (HFC-245fa); 1,1,1,3,3-pentafluorobutane (365mfc), blends consisting essentially of at least about 80% of HFC-365mfc and 1,1,1,2,3,3,3-heptafluoropropane (227ea), and combinations of any two or more of these; and   (d) a foam modifying agent selected from diols, triols and glycerols.   
     
     
         11 . A method of forming a flexible, open cell viscoelastic foam comprising:
 (a) providing a foamable, thermosetting composition capable of forming an open-cell, viscoelastic flexible foam, said composition comprising (i) one or more components capable of forming a thermoset viscoelastic matrix; and (ii) a blowing agent for forming open cells in said viscoelastic matrix, said blowing agent comprising at least one chemical blowing agent and at least one physical blowing agent selected from the group consisting of trans-1-chloro-3,3,3-trifluoropropene (HFCO-1233zd(E)), 1,1,1,3,3-pentafluoropropane (HFC-245fa); 1,1,1,3,3-pentafluorobutane (365mfc), blends consisting essentially of at least about 80% of HFC-365mfc and 1,1,1,2,3,3,3-heptafluoropropane (227ea), and combinations of any two or more of these; and   (b) forming from said foamable composition a flexible viscoelastic foam comprising a matrix comprising said thermoset polymer and a plurality of open cells in said matrix, said foam having a density of not greater than about 6 pounds per cubic foot.   
     
     
         12 . The method of  claim 11  wherein said foamable composition comprises MDI 
     
     
         13 . The method of  claim 11  wherein said foamable composition comprises TDI. 
     
     
         14 . The method of  claim 11  wherein said blowing agent comprises from about 70 to about 99 mole percent water and from about 1 to about 30 mole percent of said physical co-blowing agent. 
     
     
         15 . The method of  claim 11  wherein said foam has a density of not greater than about 4 pounds per cubic foot, said density of said foam being at least about 8 relative percent less than the density of said foam produced using the same method but without said co-blowing agent. 
     
     
         16 . The method of  claim 11  wherein said foamable composition further comprises at least one additive selected from the group consisting of 1,4 butane diol, glycerol, polyether triol, and combinations of these.